A United Nations (UN) arms expert collects samples on August 29, 2013, as they inspect the site where rockets had fallen in Damascus' eastern Ghouta suburb during an investigation into a suspected chemical weapons strike near the capital (AFP Photo) / AFP

The rebels used chemical weapons in north-eastern Syria near the border with Turkey on Tuesday, a Lebanese TV channel Al-Mayadeen reported.

The toxic shell exploded near a Kurdish defense forces’
checkpoint close to the border with Turkey in the city of Ras
al-Ayn al-Hasakah.

The attack was reported by Kurdish defense forces who are
conducting military operations against the rebels in the region.

They are quoted as saying they saw toxic yellow smoke that
followed the shell explosion, while some of them had symptoms of
severe chemical intoxication accompanied by nausea.

The reported chemical attack comes amid the second day of fierce
fighting in the town.

The Kurdish forces have successfully repelled several attacks by
armed groups of extremists of the Nusra Front ( Jabhat al-Nusra),
and the Islamic State of Iraq and the Levant, killing 28
militants.

This comes as the joint mission of UN international experts and
the Organization for the Prohibition of Chemical Weapons (OPCW)
is in Syria inspecting the sites of the toxic attacks and
destroying chemical weaponry.

The joint mission was launched after the US and its allies
threatened to apply military action on Syria following the August
21 attack in Damascus’ eastern Ghouta suburb, which killed
between dozens and 1,300 people, according to varying reports.

Syria officially became an OPCW member at the beginning of
October, in an attempt to resolve the chemical weapons issue in
the war-torn country.

Damascus also began destroying the first chemical weapons at that
time, which, according to the deal brokered by the US and Russia
in September, must be fully eliminated by June 30, 2014.

Syrian authorities have declared 23 chemical weapons sites. The
joint mission have verified 21 sites, the organization said in a
report acquired by AP on Monday.

“The two remaining sites have not been visited due to security
reasons,” the report added, suggesting that are in rebel-held
areas.

Syria has also declared 41 facilities - 18 chemical weapons
production facilities, 12 chemical weapons storage facilities,
eight mobile units to fill chemical weapons, and three chemical
weapons-related facilities - at the chemical sites where it
stored approximately 1,300 tons of precursors and agents, and
over 1,200 unfilled munitions to deliver them.

"In addition, the Syrian authorities have reported finding two
cylinders not belonging to them, which are believed to contain
chemical weapons," said Ahmet Uzumcu, chief of the global
chemical weapons watchdog, in the OPCW report.

As part of his regional trip, UN –Arab League envoy Lakhdar
Brahimi has traveled to Damascus in an attempt to gain support
for the Geneva-2 peace conference. The talks, aimed at ending the
Syrian conflict, were jointly proposed by the US and Russia.

Nineteen Syrian rebel groups announced on Sunday that they would
not take part in the peace talks, which are scheduled for the end
of November.

Russian Foreign Minister Sergey Lavrov has called threats to
undermine the talks “outrageous.”

The main opposition group, the Syrian National Coalition,
recently reiterated its demand for President Bashar Assad to step
down as a precondition for the peace conference.

Lavrov has also called on those who have influence on the Syrian
opposition to persuade them to attend so that all sides of the
conflict can take part in the Geneva-2 conference.